Railway transportation system

ABSTRACT

A transportation apparatus comprises a track formed of two cylindrical elongated elements, the facing inner surfaces of the elements constituting guide paths for traveling wheels of a carriage, the wheels lying within the area between the two track elements. Switch junctions for the track are formed with two or more switch pieces set on a rotatable member for selective location between an inlet of the junction and one or the other of the outlets thereof. The carriage has a motor-driven driving wheel which frictionally contacts one of the track elements, and apertures formed in the outer circumference of the driving wheel are capable of cooperating with pins formed on the track element surface particularly at bends of the track so as to ensure a positive drive.

United States Patent 1 1 Glastra 1 1 RAILWAY TRANSPORTATION SYSTEM Hendrik Glastra, Enschede, Netherlands [75] Inventor:

[73] Assignee: N.V. Maatschappij voor Industriele Research en Ontwikkeling, Enschede, Netherlands 22 Filed: Apr. 14, 1972 21 Appl. No.: 244,265

[30] Foreign Application Priority Data Apr. 15, 1971 Netherlands 7105013 [52] US. Cl. 104/91; 104/94; 104/101;

[51] Int. Cl. B61B 3/02; B61B 13/02; B61C 13/04 B6lC11/04; [58] Field of Search 104/87, 246, 247, 130,

104/148, 89, 91,101, 106,111; 105/29 R, 50, 30, 148, 155; 238/1, 10 E, 10 R, 29, 30, 60,63,113

[56] References Cited UNITED STATES PATENTS Wolf 105/30 X 1 Dec. 2, 1975 Primary ExaminerM. Henson Wood, Jr.

Assistant ExaminerI-loward Beltran Attorney, Agent, or FirmWatson, Cole, Grindle & Watson [57] ABSTRACT A transportation apparatus comprises a track formed of two cylindrical elongated elements, the facing inner surfaces of the elements constituting guide paths for traveling wheels of a carriage, the wheels lying within the area between the two track elements. Switch junctions for the track are formed with, two or more switch pieces set on a rotatable member for selective location between an inlet of the junction and one or the other of the outlets thereof. The carriage has a motor-driven driving wheel which frictionally contacts one of the track elements, and apertures formed in the outer circumference of the driving wheel are capable of cooperating with pins formed on the track element surface particularly at bends of the track so as to ensure a positive drive.

8 Claims, 25 Drawing Figures U.S. Patent Dec. 2, 1975 Sheet 1 of 10 3,922,970

U.S. Patent Dec.2, 1975 Sheet2of 10 3,922,970 v Sheet 3 of 10 US. Patent Dec. 2,1975

US. Patent Dec.2, 1975 Sheet4of 10 3,922,970

us. Patent Dec.2,1975 3,922,970

Sheet 6 of 10 US. Patent Dec.2', 1975 Sheet 7 of 10 wwrmw n m Rm F US. Patent Dec.2,1975 Sheet8 of 10 v 3,922,970

Sheet 10 of 10 US. Patent Dec. 2, 1975 RAILWAY TRANSPORTATION SYSTEM DISCUSSION OF THE PRIOR ART The invention relates to a transportation apparatus, adapted for the indoor transport of articles, the apparatus comprising a stationary track formed of elongated cylindrical elements and spaced apart by means of clips. A carriage is guided on the track and is driven by its own motor.

Some of the drawbacks of known transportation devices of this type are that, as a result of the manner in which the carriage wheels cooperate with the track, the track thereof cannot follow an arbitrary path and at the same time ensure that the carriage is positively guided. It is impossible to construct simple and inexpensive junction switches for the track. Moreover, such a track cannot include vertical sections so that when the track extends from one room into another, this requires the provision of large openings in the walls.

SUMMARY OF THE INVENTION The invention aims to alleviate these drawbacks and to provide a transportation device of the above mentioned type which is universally usable and which can be manufactured at low cost, while the track thereof can be built by unskilled labor.

To this end, according to the invention, the inwardly facing inner surfaces of the elements forming the track serve as a guide for the traveling wheels of the carriage lying between the track elements.

The transportation device according to the invention is relatively light in weight, is inexpensive to manufacture and the track thereof is capable of being easily installed in existing buildings. A horizontal track path can easily merge into a vertical track path over a short distance, and the track can be arranged in such a way so as to take up the least possible space. The open construction substantially avoids any dust from settling on the track, so that no cleaning of the track at regular intervals is necessary.

Druing operation, intimate rolling contact between the track elements and the traveling wheels, both formed of synthetic material, results in a substantially noiseless transportation device.

Preferably the track is assembled from a number of elements adjoining each other and coupled together by the mutual coupling of two adjoining clips each partially surrounding a track element near the end thereof.

To obtain a positive drive on, for instance, a vertical section of the track one or more of the track elements can be provided with a row of inwardly facing pins for cooperation with annular receiving apertures resiliently mounted on the carriage and located in the plane of the traveling wheels and driven by a motor. The driving wheel may also have friction areas parallel to the symmetry plane of the driving wheel, which is perpendicular to the axis of the areas cooperating with the surface of the track. Furthermore, an annular curved grooved is formed in at least some of the traveling wheels.

By the manner in which the traveling wheels of the carriage cooperate with the track, and as a consequence of the structure of the track, the junction switches which will be used in combination with the track can be simply constructed. Such switches preferably comprise an inlet and at least two outlets, a first switch piece located at the level of the track and the first outlet and connecting the inlet with this outlet, and

at least one additional switch piece located at a different level and capable of turning together with the first switch piece about an axis between the two levels, to a position in which the second switch piece is situated at the level of the inlet and a second outlet.

SUMMARY OF THE DRAWINGS FIG. 1 is a perspective showing of a room in which is arranged a transportation device with its associated track according to the invention,

FIG. 2 is a perspective view of a part of the track shown in FIG. 1,

FIG. 3 is a plan view of a curved track,

FIG. 4 is a side elevation of an are provided in the track,

FIG. 5a shows a vertical track portion at an angle of to the horizontal, and being provided with pins,

FIG. 5b shows a side view of such one of the pins shown in FIG. 5a,

FIG. 6 is a side elevation of a track portion curved in a downward direction,

FIG. 7 is a perspective view of an arc in an ascending part of the track,

FIG. 8a is a side elevation of a curve in an ascending part of the track,

FIG. 8b is a cross-section through a curved part of the track shown in FIG. 8a,

FIG. 9 is a detail view, partly in section, of the motor-transmission-driving wheel unit for a carriage, as shown in FIG. 1,

FIGS. 10a, 10b and 10c show, diagrammatically, various possible positions of the driving unit of FIG. 9,

FIGS. 10d, lOe and 10f show, diagrammatically, in plan view, these positions assumed by the driving unit,

FIG. 11 shows an embodiment of the motor and driving wheel suspension,

FIG. 12 shows, diagrammatically, a possible construction of a junction in the track, with one inlet and two inlets,

FIG. 13 shows a plan view of such a junction,

FIG. 14 shows a side elevation of the junction shown in FIGS. 12 and 13,

FIGS. 15 and 16 show, in perspective view, a practical embodiment of a junction for the track,

FIG. 17 represents, diagrammatically, a junction with one inlet and three outlets, and

FIG. 18 represents, diagrammatically, a junction with two outlets situated at different levels.

DESCRIPTION OF PREFERRED EMBODIMENTS FIG. 1 shows a room with a floor 1, the side walls 2 and 3 and a passage 4 through which a track extends into an adjacent room. A transportation track according to the invention, generally indicated by reference numeral 5, is located in the room. This track is designed to guide a carriage 6 carrying a magazine 7 for the articles to be transported. The carriage 6 has traveling wheels 6a and 6b (see FIG. 11), cooperating with portions of the track facing each other so as to establish a positive track guide, a driving motor, and an accumulator supplying the electric energy in any convenient manner. Carriage 6 will be hereinafter described in detail with reference to FIG. 11. Carriage 6 can be programmed to follow apredetermined path as by providing programming members along the track so that, for instance, postal items can be transferred from a station 8 to another designated location in a building.

FIG. 2 shows, on a.larger scale, a part of track 5 which comprises parallel cylindrical hollow track members 9, 9 maintained in spaced apart relationship by clips 10. Each clip 10 has a raised central section 11 and slightly lower sections 12, 12, respectively, at opposite ends thereof having uprights 13, 13. Curved flanges 14, 14, partially embracing track members 9, 9', are located on the uprights. Track members 9, 9 are respectively secured to these curved flanges by means of rivets l5.

Coupling pins 16 extend outwardly of the hollow ends of track members 9, 9 for coupling adjacent track members together.

A plate P, for supporting programming members for the directional control of the carriage, is shown in dotted outline in FIG. 2. The plate rests on central sections 11 of the clips and may be secured thereto through holes 18 located therein. Clips 10 may be secured against a wall or a ceiling by means (not shown) extending through holes 18 located in sections 12, 12'. And holes 19 formed in upright pieces 13, 13' may be used to secure the track members in place as by means of shackles when the members are provided around corners.

Referring back to FIG. 1 a number of variations are shown for disposition of the track. Thus, station 8 is situated below a track portion 20 provided in close proximity to wall 2, the track merging via a curved portion 21 into an ascending track portion 22 provided against wall 2. Thereafter, the track continues as a curved portion 23, a hanging track portion 24, a further curved portion 25, an arc portion 26, a second vertical track portion 27 and an arc portion 28 when it extends through passage 4 into the adjacent room. While moving along track portions 20 and 22 the magazine is in a vertical position, although it is suspended from carriage 6 on track portion 24.

The installation of the light track shown in the drawings, in existing buildings, does not require special fitting operations or significant building structural changes, so that installation can be performed without special training with reference to an instruction manual. The open construction of the track allows easy maintenance, avoids dust traps and the necessity of periodic track cleaning. Due to the fact that the carriage 6 carries its own source of energy such as an accumulator as hereinabove described, it is not necessary to provide track 5 with additional current supply rails and the like, so that the risk of short circuits is eliminated and a simple construction of the track is obtained.

FIG. 3 shows a plan view of a bend in the track. The straight portions parts 29, 29' are interconnected near an end thereof by means of a clip 30 and curved portions 31, 31' are interconnected near an end thereof by means of a clip 30'. Clips 30 and 30 are coupled together by coupling pieces 32. This kind of coupling makes it possible, when loosening coupling pieces 32 and the clips, provide an opening at a selected location in the track, through which a carriage can be removed. The other ends of the curved portion 31, 31' of the track are coupled together via coupling pins 33 to a straight part of the track. Clips 30, similar to clips 10, are used for securing the remaining portions of the track in place.

In securing an arcuate portion 34 of the track in place, as in FIG. 4, clips 35 are connected to clips 10 through holes 19. The curve shown in this Figure corresponds to curve 27 shown in FIG. 1.

In order to obtain a positive and non-slip drive at in clined portions of the track, that portion of the track members cooperating with the drive wheel of the carriage is provided with equally spaced pins extending toward the other track member. The pins cooperate with apertures in the driving wheel.

FIGS. 5a shows a vertical portion 36 of the track comprising elements 37, 37, element 37 being provided with a row of pins 38 extending toward element 37 The elements are again interconnected by means of clips 39 similar to clips 10. FIG. 5b shows pin 38 in detail, the free end 38a thereof being of a four-sided frustro-pyramidal shape. The angle between the sides and the pin axis is about 10.

FIG. 6 shows a side elevation of a vertical curved portion comprising elements 40, 40, pins 41 being provided on outer element 40 of the bend.

FIG. 7 shows a vertical portion 42 of the track which merges via an arc portion 43 into a horizontal portion 44 of the track. Track elements 45 is provided with pins 46 extending toward track element 45 These pins are provided over a short distance at portion 44 in order to ensure a proper transition of the vertical portion into the horizontal portion.

FIG. 8a shows another bend arrangement in which vertical portion 47 merges into horizontal portion 48, track element 49 being provided with pins 50 extending toward the opposite track element 49. As FIG. 8a shows, the length of the free end of pin 50 increases and decreases gradually at the beginning and the end of a row. This ensures that the pins gradually enter the corresponding apertures in a carriage drive wheel without shocks.

FIG. 8b shows a cross-section of a track member such as 49 where it is provided with pins 50. Longitudinal grooves 49a and 49b are formed on track member 49 on opposite sides of the row of pins 50. These grooves are so dimensioned that flanges 51a, 51b of driving wheel 5 do not touch the track; only the center portion 51a touches the track. This center portion is provided with apertures 51d located at regular intervals and cooperating with pins 50. These measures ensure, as has been shown in practice, a quiet movement of the carriage along the track.

As shown in FIG. 9, driving means 52 together with transmission 53 and driving wheel 54 of a carriage constitute a unit which, in a manner to be discussed hereinafter, is suspended in the frame. The driving wheel 54 is provided with a circumferential groove 55 in which are disposed two spaced rings 56, 56 formed of a material having a high coefficient of friction. The rings cooperate with a track member 57 and contact the same.

A ring of short pins 58 is incorporated in driving wheel 54, the center to center distance of pins 58 corresponding to the pitch of driving pins 50 provided on the track when needed. The unit cooperates with the track in the same way as shown in FIG. 8. For example, for a portion of the track provided with pins 50, rings 56, 56 fit into grooves 49a, 49b and pins 58 of the driving wheel bear upon the portion of the track between the grooves. This adds to achieving a quiet movement of the carriage along such a portion of the track.

On rounding a bend driving wheel 54 should obviously always be in contact with the track. This requires a special suspension of the motor-driving unit. This unit should not only be resiliently suspended in a direction perpendicular to the center line of the carriage, which is necessary for it to maintain contact with the track on rounding a curve, but should moreover be capable of pivotal motion about an axis parallel to the center line of the carriage, which is necessary for it tomaintain contact with the track on rounding a curve. A resilient suspension is furthermore necessary to ensure that at the beginning of a row of pins on the track, these pins can engage with the openings of the driving wheel.

FIGS. a, 10b and 100 respectively show the positions of a motor-driving unit 59, similar to that shown in FIG. 9, when a curve is rounded toward the left, when a straight path is followed, and when a curve is rounded toward the right.

FIGS. 10d, lOe and 10f show diagrammatically a plan view of this driving unit 59 and clarify also how the pairs of traveling wheels 6a, 6b of the carriage unit be able to turn around an axis perpendicular to the center line of the carriage on rounding a curve. This means that suitable guides, not shown in the FIGS. 10a to 100, should be used for allowing these movements yet retaining the entire carriage in a correct position.

The guides must be such that the motor-driving unit can perform the required tilting movements on rounding bends and the traveling wheels can assume the required angular position and, while on rounding bends, the traveling wheels can move away from each other and the driving wheel can always be maintained in contact with the track.

Carriage 6 including the motor driving unit thereof is shown in FIG. 11 mounted in place between track members 9 and 9' of the track. Motor 60 and reduction gearing 61, on the shaft of which driving wheel 62 is mounted, are supported by fastening plate 63 which has bent-over side edges 64. The carriage also includes an accumulator (not shown) supplying electric energy to the motor in any normal manner. Pins 65, parallel to track members 9 and 9', extend outwardly of edges 64 of the plate. Each pin is guided in an elongated slot 66 arranged perpendicular to the longitudinal direction of the carriage and provides in guide block 67 mounted on a support plate 68 of carriage 6. Pins 64 are also guided along a bore (not shown) provided in bent-over edge 69 of a second fastening plate 70 which, by means of elongated guide slots 71 and pins 72 extending therethrough and mounted on the carriage, are guided in such a manner that plate 63 is movable in a vertical direction. A guide shaft 73 is disposed for sliding movement in a holder 74 mounted on plate 70. A pressure roller 75 is located on guide 73 which, due to spring tension, is pressed against track member 9.

As pointed out earlier, the track is particularly light which gives rise to the possibility of providing various junction switching constructions in a unique manner. Basically, track portions are coupled to each other at different levels, and can be turned around an axis of rotation situated in such a manner that, for a particular angular displacement thereof, a portion of the track establishing a particular connectionis turned away and is replaced with another track portion establishing another connection.

An example of this is shown in FIG. 12 wherein a switch member has one inlet and two outlets. The FIG- URE illustrates the manner in which a portion 76 of the track should be connected with either a straight track portion 77 or with a portion 78 of the track which branches off to the left. The switch member for such purpose comprises a straight portion 79 of the track which, in'FIG. 12, is shown in the position in which it interconnects portions 76 and 77 of the track. This straight portion 79 is coupled to a bent portion 80 of the track which is located under the straight portion. The coupling is diagrammatically represented by connections 81 located between the fastening clips of the respective track portions.

-A tilting movement of the combination of track portions 79 and 80 about a shaft 82 located therebetween results .in portion 79 lying at a lower level previously occupied by track portion 80, while portion 80 lies at the original level of portion 79 and thereby establishes a connection between the end of portion 76 and the beginning of portion 78. The light construction of the track allows for the provision of such a switch junction, the operation of which requires only a moderate force.

FIGS. 13 and 14 show in plan view and side elevation, respectively, a possible embodiment of such a switch member. Incoming portion 83 of the track mounted on a wall or base 84 reaches a higher level portion 85 via bent intermediate portion 86 and terminates at end 86a. The outlet of the switch, leading in the same direction begins at end 87 and merges from straight portion 85, via bent portion 88, into a portion 89 located at the original level. There is, however, a branching section provided to the left.

Under the movable straight switch portion 90 of the track is located a curved switch portion 91 for establishing a connection between track portion 85 and branching section 92. Portions 90 and 91 of the switch may, due to a driving mechanism (not shown), turn about the pivots 93 located halfway between track portions 90 and 91. When such a tilting movement is performed, portion 91 comes to lie at the level which portion 90 of the track originally occupied, thereby interconnecting portions 85 and 92 of the track.

The principle on which the construction of the junction switches is based is applicable to many variants, one of which is represented in outline in FIG. 17. Due to the application of three different switch pieces, arranged at angles of 120 relative to each other and mutually coupled so as to be capable of turning around a common axis, it is possible to obtain a junction switch with one inlet and three outlets. The junction switch comprises a straight piece 94 and two curved pieces 95, 96 which can turn around the axis 97. In this way it is possible to selectively establish a connection between track portion 98 and track portion 99 coaxial therewith between portion 98 and portion 100 of the track leading to the right; and between portion 98 and track portion 101 leading to the left.

FIGS. 15 and 16 are perspective views of an embodiment of a junction switch. The switch is mounted on a support plate 102, on one side of which is provided a curved track portion 103, and on the other side of which is provided a straight track portion 104. Plate 102 is rotatably mounted, via pins 105 and 106, in a frame generally designated 107. In the position shown, curved portion 103 establishes a connection between the track portion 108 and track portion 109 perpendicular thereto. In the other position of the junction switch a connection is established between track portion 108 and track portion 110 coaxial therewith. It should be noted that for the sake of clarity segments of track portions-108 and 109 are represented in broken lines only.

The switch is provided with locking members for locking the switch in a particular adjusted position.

These locking members comprise fingers 111a and" lllb linked by a coupling rod 112 and capable of turning about an axis which is parallel to the axis of rotation of switch plate 102 and of locking fingers 113a and l13b coupled in a corresponding manner and likewise rotatable about an axis which is parallel to the axis of rotation of the switch. In the locked position, which is the normal operative position, the free ends of the four locking fingers 111a, lllb, 113a, ll3b are in contact with the back side of plate 102 in the vicinity of the corners thereof, as FIG. shows in relation to locking finger 111a. The plate is thereby fixed against rotation in both directions. A change of the position of the switch is only then possible when locking fingers 111a and lllb have been turned upwardly and locking fingers 113a and 11312 have been turned downwardly, so that plate 102 can freely turn. FIG. 16 illustrates such a turning movement of the plate. The driving of the locking fingers and the switch should be carried out in such a way that at first the locking fingers are moved from their locking position and thereupon plate 102 is rotatably driven. It is conceivable to operate the locking fingers by means of an electromagnet which is excited before the electric motor driving the plate is energized. Also a mechanical system with a slip coupling and a particular free stroke in the drive can be employed. The FIGURES show a drive means in the form of an electric motor 114 and a driving chain 115 connected to a driving mechanism 116 wherein a selected free stroke is produced for driving plate 102 in such a way that in the first phase of the movement a presser rod 117 coupled to locking finger 111a constitutes an upward stroke whereby the locking fingers enter the unlocking position; thereupon shaft 105 of plate 102 is rotated. It is obvious that for lower locking fingers 113a and 113b, an analogous drive is provided by means of a presser rod not shown in the FIGURES.

The entire switch is enclosed in a housing having on the front side thereof a recess corresponding to the dimensions of plate 102. The back wall of this housing is visible in the drawing and is denoted by reference numeral 118. The cover is fixed in position on protruding supports 119. The housing also contains electronic checking and control apparatus contained within housing 120.

As will be clear from reference to FIG. 3 the track elements can be coupled to each other by means of securing clips (not shown) provided at the vicinity of the ends thereof, which are coupled to each other by means of coupling plates (also not shown). FIGS. 15 and 16 show a plurality of such coupling plates 121 in the vicinity of the ends of the stationary track elements.

FIG. 18 represents another embodiment of a switch wherein switch piece 122 establishes, depending on its position with respect to axis 123, a connection between track portion 123 and track portion 124 or between portion 123 and track portion 125.

From the foregoing it is obvious that the basic design of the apparatus according to the invention allows for a great number of variations so that, in nearly completed rooms, the track can be arranged with a minimum of structural disturbance and constructional work. Due to the simple construction of the track, when standard pieces are used, it is possible to have the track built without special training; the track can be made available in kit form, whereby only the assistance of specialized skilled workmen is required for applying and programming the control members.

What I claim is:

1. 'A transportation apparatus comprising at least one pair of spaced apart, cylindrical, elongated elements defining at least one track, clips interconnecting said elements together in spaced-apart relationship, a carriage guided on said elements and being located therebetween, travelling pulley-type wheels on said carriage also lying between said elements and being in rolling contact with the opposing and inwardly facing portions of said elements, a driving wheel resiliently supported on said carriage and lying in the plane of said travelling wheels, said driving wheel having spaced friction means thereon in rolling contact with one of said elements, and a motor operatively connected to said carriage through reduction gearing for driving said drive wheel.

2. The apparatus according to claim 1 wherein said one of said elements in provided with a row of spaced pins extending toward the other of said elements, said driving wheel being provided with a plurality of spaced receiving apertures in the outer periphery thereof for cooperation with said spaced pins as said carriage is driven along said track, and at least one of said travelling wheels having an annular groove along its outer periphery.

3. The apparatus according to claim 2 wherein the free ends of said pins are each of a four-sided frustopyramidal shape, and the length of said pins in the row gradually increase and decrease respectively near the beginning and the end of the row.

4. The apparatus according to claim 1 wherein two spacer pair of said travelling wheels are provided, said driving wheel, reduction gearing and motor constituting a single unit and being located between said spaced pair of wheels and said unit being supported for movement in a direction of the axis of rotation of said driving wheel and for movement in a direction of the longitudi nal axis of said carriage.

5. The apparatus according to claim 4 wherein said unit is mounted on a transversely extending fastening plate, transversely extending guide pieces secured to said carriage, elongated guide slots in said guide pieces, guide pins on said fastening plate extending through said guide slots for guiding said fastening plate relative thereto, a second fastening plate having bent-over edges, elongated openings in said second plate, guide pins on said carriage extending through said second plate openings, said second plate being guided by said carriage pins and being slideable in a transverse direction to the longitudinal axis of said carriage, a carrier for a presser wheel being located on said second plate. said presser wheel being in rolling contact with said other of said elements, and spring means for resiliently guiding said carriage in a transverse direction to the longitudinal axis of said carriage.

6. The apparatus according to claim 1 wherein another pair of said elements are provided defining another track intersecting said one track and lying in the same plane, a junction switch track means located at the intersection of and interrupting said two tracks, said switch track means including a support plate having at least two sides and being mounted for rotation about its longitudinal axis, track sections respectively mounted on said two sides, one of said track sections forming a portion of said one track and the other of another track intersecting said one track and lying in the same plane therewith, said support plate having three sides, with track sections mounted on each side thereof, respective ones of said track sections forming a portion of said tracks upon rotation of said support plate, whereby each of said tracks are alternately interrupted and made continuous upon rotation of said support plate. 

1. A transportation apparatus comprising at least one pair of spaced apart, cylindrical, elongated elements defining at least one track, clips interconnecting said elements together in spaced-apart relationship, a carriage guided on said elements and being located therebetween, travelling pulley-type wheels on said carriage also lying between said elements and being in rolling contact with the opposing and inwardly facing portions of said elements, a driving wheel resiliently supported on said carriage and lying in the plane of said travelling wheels, said driving wheel having spaced friction means thereon in rolling contact with one of said elements, and a motor operatively connected to said carriage through reduction gearing for driving said drive wheel.
 2. The apparatus according to claim 1 wherein said one of said elements in provided with a row of spaced pins extending toward the other of said elements, said driving wheel being provided with a plurality of spaced receiving apertures in the outer periphery thereof for cooperation with said spaced pins as said carriage is driven along said track, and at least one of said travelling wheels having an annular groove along its outer periphery.
 3. The apparatus according to claim 2 wherein the free ends of said pins are each of a four-sided frusto-pyramidal shape, and the length of said pins in the row gradually increase and decrease respectively near the beginning and the end of the row.
 4. The apparatus according to claim 1 wherein two spacer pair of said travelling wheels are provided, said driving wheel, reduction gearing and motor constituting a single unit and being located between said spaced pair of wheels and said unit being supported for movement in a direction of the axis of rotation of said driving wheel and for movement in a direction of the longitudinal axis of said carriage.
 5. The apparatus according to claim 4 wherein said unit is mounted on a transversely extending fastening plate, transversely extending guide pieces secured to said carriage, elongated guiDe slots in said guide pieces, guide pins on said fastening plate extending through said guide slots for guiding said fastening plate relative thereto, a second fastening plate having bent-over edges, elongated openings in said second plate, guide pins on said carriage extending through said second plate openings, said second plate being guided by said carriage pins and being slideable in a transverse direction to the longitudinal axis of said carriage, a carrier for a presser wheel being located on said second plate, said presser wheel being in rolling contact with said other of said elements, and spring means for resiliently guiding said carriage in a transverse direction to the longitudinal axis of said carriage.
 6. The apparatus according to claim 1 wherein another pair of said elements are provided defining another track intersecting said one track and lying in the same plane, a junction switch track means located at the intersection of and interrupting said two tracks, said switch track means including a support plate having at least two sides and being mounted for rotation about its longitudinal axis, track sections respectively mounted on said two sides, one of said track sections forming a portion of said one track and the other of said track sections forming a portion of said another track upon rotation of said support plate, whereby each of said tracks are alternately interrupted and made continuous upon rotation of said support plate.
 7. The apparatus according to claim 6 wherein said switch means further includes means for locking said support plate upon rotation thereof in alternate positions of rotation thereof.
 8. The apparatus according to claim 6 wherein still another pair of said elements are provided defining still another track intersecting said one track and lying in the same plane therewith, said support plate having three sides, with track sections mounted on each side thereof, respective ones of said track sections forming a portion of said tracks upon rotation of said support plate, whereby each of said tracks are alternately interrupted and made continuous upon rotation of said support plate. 